Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus of the Flaviviridae family and has worldwide distribution, being one of the main causes of economic losses in cattle raising. The genome of pestiviruses is a single strand of positive-sense RNA with a length of 12.3 kb, which encodes one open reading frame flanked by untranslated regions. E2 glycoprotein is required for binding to cell-surface receptors and it also contains major antigenic determinants. The nucleotide sequence coding E2 is the most variable part of the viral genome. The heterogeneity that exists among circulating strains causes problems in the development of effective vaccines and reliable diagnostics. In this study, and for the first time analysis was made of the E2 glycoprotein coding sequences of 14 Polish BVDV-1 strains which belong to four subtypes: 1b (n = 7), 1f (n = 3), 1s (n = 3), and 1r (n = 1). These sequences showed evidence of strong purifying (negative) selection. However, we also identified positively selected sites. The availability of E2 sequences of Polish BVDV strains for reference, knowledge gained through epitope prediction attempts, and information on protein glycosylation sites can afford a better understanding of host-pathogen interactions.

中文翻译：

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波兰牛的牛病毒性腹泻病毒E2蛋白编码序列的变异性。

牛病毒性腹泻病毒（BVDV）属于黄病毒科的瘟病毒属，在世界范围内分布，是养牛造成经济损失的主要原因之一。瘟病毒的基因组是一条正链RNA的单链，长度为12.3 kb，编码一个旁接非翻译区的开放阅读框。E2糖蛋白是结合细胞表面受体所必需的，并且它还包含主要的抗原决定簇。编码E2的核苷酸序列是病毒基因组中变化最大的部分。循环菌株之间存在的异质性在开发有效疫苗和可靠诊断方面引起问题。在这项研究中，我们首次对14种波兰BVDV-1菌株的E2糖蛋白编码序列进行了分析，这些菌株属于4个亚型：1b（n = 7），1f（n = 3），1s（n = 3）和1r（n = 1）。这些序列显示了强纯化（阴性）选择的证据。但是，我们还确定了积极选择的地点。波兰BVDV菌株E2序列的可利用性，通过表位预测尝试获得的知识以及有关蛋白质糖基化位点的信息可以更好地理解宿主与病原体的相互作用。